Caloric restriction (CR: reducing caloric intake 30-40 percent below ad libitum levels) has been repeatedly shown to extend lifespan, reduce the incidence and delay the onset of age-related disease, enhance stress protection, and attenuate functional decline in mammals. The NIA longitudinal study of CR and aging in rhesus monkeys is in its 25th year and recently published the survival findings. We reported findings of improved health; however, unlike findings from a similar study at the University of Wisconsin, the NIA CR monkeys did not have improved survival compared to the controls. Both studies are ongoing and we will continue to monitor the monkeys for age-related changes in many health parameters. Specifically we have ongoing studies assessing behavior including locomotor and motor performance. We have recently completed eye exams identifying traits consistent with macular degeneration. The monkeys have now had 5 exams in the last 7 years. We completed sample collection to identify markers consistent with intestinal cancers that might be similar between monkeys and humans. Additionally, fecal samples will be analyzed for the gut microbiota and compared to monkeys on the Wisconsin study and humans practicing CR.